html中行内调用function的时候,是通过window调用的function，所以打印this等于打印window，所以在使用行内注册事件时务必传入参数this
<!DOCTYPE html><html><head lang="en"> ???<meta charset="UTF-8"> ???<title></title> ???<style> ???????.wrong { ???????????border: 2px solid red; ???????} ???????.right { ???????????border: 2px solid #91B81D; ???????} ???</style></head><body> ???账号：<input type="text" name="name" value="" onblur="fn(this)" /><br /><br /> ???密码：<input type="text" name="name" value="" onblur="fn(this)"/> ???<script> ???????function fn(ele) { ???????????if (ele.value.length < 6 || ele.value.length > 12) { ???????????????ele.className = "wrong"; ???????????} else { ???????????????ele.className = "right"; ???????????} ???????} ???</script></body></html>JS——行内式注册事件
原文地址：http://www.cnblogs.com/wuqiuxue/p/7873650.html